Plesk offers us an option called Applications, where we can install CMSs, forums, and more with just a couple of clicks. To do this, you must access the Subscription you want to manage. Below in the options, there is one called Applications, where if you click it, the following window will appear:

The window that appears shows us the installed applications we have. In case we don't have any, this screen will appear to install Wordpress, Joomla, or Drupal.
Now we will take the opportunity to explain a bit what each section shown on the left is for:

Manage my applications

From the following window, it is possible to view information about all installed applications. The value 'None' in the 'Installation Path' column means that the application is external. This application cannot be installed on any of your websites; it only provides a link to an external service.

Featured Applications

From here, it is possible to manage the featured applications that we can find in the Plesk Panel installers. Normally, the featured applications are Wordpress, Joomla, and Drupal.

All available applications.

We can see all commercial and free applications on their websites. APS format applications can be installed on your websites with just a few clicks.
At the top, we have a search engine in case we want to search for a specific application, to check if Plesk supports auto-installation.

Here we have a guide on how to install Prestashop (for all applications, the steps would be the same): https://www.profesionalhosting.com/soporte-en-linea/guias-de-prestashop-wordpress-magento/instalar-prestashop-con-el-instalador-de-plesk.html